Field of the Invention
The present invention relates to a solar cell unit.
Description of the Background Art
A solar cell module is known from EP 2 073 279 A1, which corresponds to US 2010/0132793, in which a semiconductor body formed as a solar cell is arranged on a substrate. In order to protect the semiconductor body and particularly the side surfaces thereof from environmental influences, which lead to a degradation of the electrical parameters, a frame is arranged on four sides around the semiconductor body and closed with a transparent cover. Next, the remaining interspace is filled with a transparent sealing compound and an optical element is attached.
Another solar cell unit is known from EP 1 953 825 A2, which corresponds to U.S. Pat. No. 7,264,378. In this case, a semiconductor body formed as a solar cell is arranged on a substrate. Then, to protect the semiconductor body a sealing film and a package, which consists of a number of parts and also comprises an optical element, are arranged on the substrate in a multistep process.
A solar cell unit is known from DE 10 2009 006 286 A1, which corresponds to U.S. Pat. No. 8,093,492, and which has a plurality of individual solar cells on a substrate. Inter alia, an optical element, which is also called a secondary optical element “SOE,” is arranged above the solar cell. The optical element guides the sunlight focused by a Fresnel lens to the surface of the solar cell. Large-area solar cell units can be constructed by means of the focusing arrangement with a few small solar cells with an efficiency up to 40% and higher.